The broad long-term objective of this research is to inform the development of interventions that will improve access to, use of, and quality of post-acute rehabilitation care for underserved populations. The primary objective of the proposed study is to gain a more thorough and current understanding of disparities in the use of post-acute rehabilitation care following hip fracture, joint replacement, and stroke. This study proposes to pool and analyze state-specific hospital discharge data from four geographically and demographically diverse states (AZ, FL, NJ, WI). The hospital discharge data will be merged with data from the American Hospital Association Annual Survey database, the Area Resource File, and U.S. Census data. Descriptive, bivariate, and multivariable regression analyses for discrete outcomes, including multi-level analyses, will be conducted for each condition to achieve the following specific aims: 1) Describe the sociodemographic (race, ethnicity, age, gender, socioeconomic status) and geographic disparities (urban/rural, state) in the use of post-acute rehabilitation care. Through descriptive and bivariate analyses of the data, we will determine the extent to which use of post-acute rehabilitation care varies by each sociodemographic and geographic characteristic. 2) Determine the extent to which identified sociodemographic and geographic disparities are explained by other observed characteristics. Through a series of multivariable analyses examining individual and community-level characteristics associated with the use of post-acute rehabilitation care and through the use of decomposition techniques we will determine the extent to which the identified disparities are explained by other observed characteristics. More specifically, we will determine the extent to which the identified disparities are: a. confounded by other observed characteristics (e.g., insurance status and/or disease severity may explain some of the racial differences in use;marital status may explain some of the gender differences in use);b. moderated by other observed characteristics (e.g., disparities in use may differ for low income and high income minorities);c. explained by individual versus community-level characteristics (we hypothesize that both individual and community-level factors will explain differences in use);and d. unexplained by the characteristics examined in this study (we hypothesize that some of the identified differences in use will be unexplained). PUBLIC HEALTH RELEVANCE: Post-acute rehabilitation care is an effective and growing area of health care that has not been adequately investigated in regard to health care disparities. Identifying the extent to which disparities exist in post-acute rehabilitation care and determining underlying reasons for these disparities are necessary first steps in developing interventions to eliminate these disparities.